Ink compositions, processes for making them and uses thereof

ABSTRACT

An ink composition comprising a water-soluble reactive dye comprising at least three chromophoric groups linked to a polyamine; and a medium comprising at least one of a low melting point solid, an organic solvent and a mixture of water and one or more water-soluble organic solvent(s).

The present invention relates to compositions and solutions thereof,suitable for use in printing and imaging technologies, especially thosesuitable for coloration of substrates such as paper, plastics, textiles,metal and glass by printing processes such as ink jet printing and thosesuitable for use in electrophotography such as toners.

Ink jet printing is a non-impact printing technique which involvesejecting, thermally or by action of an oscillating piezo crystal,droplets of ink continuously or on demand from a fine nozzle directlyonto a substrate such as paper, plastics, textile, metal or glass. Theink may be aqueous, solvent or hot melt based and must provide sharp,non-feathered images which have good waterfastness, light fastness andoptical density, have fast fixation to the substrate and cause noclogging of the nozzle.

Electrophotographic copiers or printers generally comprise an organicphotoconductor (OPC) and a developer or toner. The OPC generallycomprises an electrically conducting support, a charge generating layerand a charge transport layer. The electrically conducting support is ametal drum, typically an aluminium drum, or a metallised polymer film,typically aluminised polyester. The charge generating layer comprises acharge generating material (CGM) and a binder resin, typically apolycarbonate. The charge transport later comprises a charge transportmaterial (CTM) and a binder resin, typically a polycarbonate. Thedeveloper or toner comprises a toner resin, a colorant and optionally acharge control agent (CCA). The toner resin is typically a styrene orsubstituted styrene polymer or styrene-butadiene copolymer. The colorantis typically a dye or pigment or mixture thereof.

According to a first feature of the present invention there is providedan ink composition comprising a water-soluble reactive dye comprising atleast three chromophoric groups linked to a polyamine; and a mediumcomprising at least one of a low melting point solid, an organic solventand a mixture of water and one or more water-soluble organic solvent(s).

The water-soluble reactive dye preferably comprises 3, 4 or 5, morepreferably 3 or 4, especially 3 chromophoric groups linked to apolyamine. The chromophoric groups can be different from each other, butthey are preferably identical to each other.

The polyamine to which the chromophoric groups are linked preferablyconsists of at least three amino groups, more preferably three to six,especially three or four amino groups, joined together by optionallysubstituted aliphatic groups. The amino groups are preferably attachedto one or two --CH₂ -- groups (as illustrated in --HN--CH₂ -- and --CH₂--N(-)--CH₂ --). Preferred polyamines are linear polyamines, for exampleof the Formula (I), or branched polyamines, for example of Formula (II),wherein each R¹ independently is H or optionally substituted alkyl, nhas a value of 2 to 10, preferably 2 to 6, more preferably 2, and p hasa value of 2 to 6, more preferably 2 or 3: ##STR1##

Reactivity of the dyes is preferably provided by means of a reactivetriazine or pyrimidine group, more preferably a reactive triazine grouplinking the chromophoric groups to amino groups in the polyamine. Thereactive triazine group is preferably an s-triazine group having alabile atom or group at the 2-,4 or 6-position, for example a group ofthe formula: ##STR2## wherein Y is a labile atom or group.

In light of the above preference for amino groups being attached to--CH₂ -- groups and the chromophoric groups being linked to the nitrogenatoms by means of reactive triazine groups it is preferred for thewater-soluble reactive dyes to contain at least 3, more preferably 3,4or 5, especially 3 or 4, more especially 3 groups of the Formula (III):##STR3## wherein: m is from 1 to 6;

Q is H or optionally substituted alkyl or alkylene;

Y is a labile atom or group; and

D is a chromophoric group.

Preferably m is 2, 3 or 4, more preferably 2 or 3, especially 2.

Q is preferably H, C₁₋₄ -alkyl or C₂₋₄ -alkylene, more preferably H,methyl or --CH₂ CH₂ --, especially H or --CH₂ CH₂ --.

As will be understood, when Q is H or optionally substituted alkyl thechromophoric group D is a chain terminating chromophoric group and whenQ is optionally substituted alkylene then D is a pendent chromophoricgroup. Thus a dye comprising three chromophoric groups linked todiethylene triamine would have two terminating chromophoric groups andone pendent chromophoric group. When the polyamine istris(2-aminoethyl)amine the corresponding dye would have threeterminating chromophoric groups and zero pendent chromophoric groups.

One preferred class of dye, is of the formula N(Z)₃ wherein each Zindependently is of the formula (III) defined above, with the provisothat Q is H or optionally substituted alkyl, preferably H or C₁₋₄-alkyl, especially H.

A second preferred class of dye of the Formula (IV): ##STR4## wherein tis 2, 3 or 4;

r is 3, 4or 5;

q is (t+3)-r; and

Y, R¹, m and D are as hereinbefore defined.

In a preferred embodiment the dye is of Formula (III) wherein at leastone D is a chromophore other than an azo chromophore.

R¹ is preferably H or C₁₋₄ -alkyl, more preferably H.

By a labile atom or group it is meant an atom or group which is bound bya chemical bond to the triazine nucleus, which atom or group isdisplaceable by a hydroxyl group of cellulose under mildly alkalineaqueous conditions to form a covalent bond between the triazine nucleusand cellulose. As examples of such atoms or groups there may bementioned halogen atoms, for example F and Cl; sulphonic acid groups;thiocyano groups; quaternary ammonium groups, for exampletrialkylammonium groups and optionally substituted pyridinium groups,for example 3- and 4-carboxy pyridinium groups.

When R¹, Q or an aliphatic group is substituted the substituent ispreferably selected from hydroxy, amino, halo, carboxy and sulpho.

In a preferred embodiment the dye is free from --SO₂ CH═CH₂ groups andgroups which are convertible on treatment with aqueous alkali to --SO₂CH═CH₂ groups (e.g. --SO₂ CH₂ CH₂ OSO₃ H, --SO₂ CH₂ CH₂ SSO₃ H, --SO₂CH₂ CH₂ OPO₃ H and --SO₂ CH₂ CH₂ Cl). Preferably the only reactivegroups in the dyes are reactive triazine groups.

The chromophoric groups preferably each independently comprise an azo,anthraquinone, phthalocyanine, triphenodioxazine or formazan group.

Preferred azo groups are monoazo and disazo groups. Preferred monoazogroups are formula L--N═N--L¹ --NR¹ -- wherein L is an aryl orheteroaryl group, L¹ is an arylene group and R¹ is as hereinbeforedefined.

It is preferred that each aryl or arylene group independently is a mono-or di-cyclic aryl or arylene group. Preferred aryl groups are optionallysubstituted phenyl and optionally substituted naphthyl, and preferredarylene groups are optionally substituted phenylene and optionallysubstituted naphthylene. Preferred heteroaryl groups are pyridonyl andpyrazolonyl.

A first preferred monoazo group is of the Formula (VI) or salt thereof:##STR5## wherein: X is H or sulpho; and

L and R¹ are as hereinbefore defined.

L is preferably optionally substituted phenyl or naphthyl, especially aphenyl or naphthyl group having at least one sulpho substituent. Furtheroptional substituents which may be present on L include a halogen atom,especially chlorine; an alkyl radical, especially C₁₋₄ -alkyl, moreespecially methyl; an acylamino radical, especially acetylamino,benzamido or sulphonated benzamido; amino; hydroxy; and an alkoxyradical, especially C₁₋₄ -alkoxy, more especially methoxy.

As examples of phenyl groups having at least one sulpho substituentthere may be mentioned 2-, 3- or 4-sulphophenyl; 2-sulpho-4-nitrophenyl;2-sulpho-5-nitrophenyl; 4-sulpho-2-methylphenyl;5-sulpho-2-methylphenyl; 2-sulpho4methylphenyl;5-sulpho-2-methoxyphenyl; 2-sulpho4-methoxyphenyl;4-sulpho-2-chlorophenyl; 5-sulpho-2-carboxyphenyl; 2,4-disulphophenyl;2,5-disulphophenyl; and 3,5-disulphophenyl.

As examples of naphthyl groups having at least one sulpho substituentthere may be mentioned 1-sulphonaphth-2-yl; 1,5,7-trisulphonaphth-2-yl;3,6,8-trisulphonaphth-2-yl; 5,7-disulphonaphth-2-yl;6-sulphonaphth-2-yl; 4,5-, 6-, or 7-sulphonaphth-1-yl;4,8-disulphonaphth-1-yl; 3,8-disulphonaphth-1-yl;2,5,7-trisulphonaphth-1-yl; and 3,5,7-trisulphonaphth-1-yl.

Preferred optional substituents which may be present on L¹ are thosementioned above for L.

In groups of Formula (VI), --NR¹ -- is preferably at the 6-, 7- or8-position, especially the 6- or 8-position. When --NR¹ -- is at the8-position, it is preferred that X is a sulpho group at the 5- or6-position.

A second preferred monoazo group is of the Formula (VII) or a saltthereof: ##STR6## wherein: R³ is H or C₁₋₄ -alkyl;

R² is H. C₁₋₄ -alkyl, C₁₋₄ -alkanoyl or optionally substituted benzoyl,especially benzoyl or sulphobenzoyl, acetyl, propanoyl, n-butanoyl oriso-butanoyl; and

X and R¹ are as hereinbefore defined.

A third preferred monoazo group is of the Formula (VIII) or saltthereof: ##STR7## wherein: Ph is an optionally substituted phenyl group,especially sulphophenyl;

R⁴ is CN, CH₃ or carboxy; and

R¹ and X are as hereinbefore defined.

A fourth preferred monoazo group is of the Formula (IX) or saltsthereof: ##STR8## wherein: R¹ and X are as hereinbefore defined;

R⁵ is C₁₋₄ alkyl or phenyl;

R⁶ is H, --CN, --NO₂, --CONH₂, --CONH(C₁₋₄ alkyl) or --CO(C₁₋₄ alkyl)₂ ;and

R⁷ is H, optionally substituted C₁₋₆ alkyl, optionally substitutedphenyl or optionally substituted naphthyl.

It is preferred that R⁵ is methyl.

Preferred optional substituents which may be present on R⁷ are ashereinbefore defined for L.

A preferred disazo group is of Formula (X) or salt thereof:

    L--N═N--A--N═N--B--NR.sup.1 --                     Formula (X)

wherein:

A and B are each independently optionally substituted phenylene ornaphthylene; and

R¹ and L are as hereinbefore defined.

It is preferred that B is optionally substituted naphthylene and A isoptionally substituted phenylene. The optional substituents which may bepresent on A or B are preferably independently selected from halo,especially chloro; alkoxy, especially C₁₋₄ -alkoxy; alkyl, especiallymethyl; sulpho; carboxy; hydroxy; amino; acylamino especially asacetamido, benzamido and sulphonated benzamido, and pyrimidinylamino ortriazinylamino cellulose-reactive groups.

As Examples of groups represented by A and B there may be mentioned-phenylene, sulphophenylene, ureidophenylene, 7-sulpho-1,4-naphthylene,6-sulpho-1,4-naphthylene and 8-sulpho-1,4-naphthylene.

A preferred anthraquinone group is of the Formula (XI) or a saltthereof: ##STR9## wherein the anthraquinone nucleus optionally containsa sulphonic acid group in the 5-, 6-, 7-, or 8-position; V is a divalentorganic linking group, preferably of the benzene series; and R¹ is ashereinbefore defined.

V is preferably phenylene, diphenylene, or 4,4'-divalent stilbene orazobenzene radicals which are optionally sulphonated. It is preferredthat V contains one sulphonic acid group for each benzene ring presenttherein.

A preferred phthalocyanine group is of the Formula (XII) or a saltthereof: ##STR10## wherein Pc is a metallo-phthalocyanine nucleus,preferably copper or nickel phthalocyanine; each R¹ is as hereinbeforedefined; each W independently is a hydroxy or a substituted orunsubstituted amino group, V¹ is a divalent organic linking group,preferably a C₁₋₄ -alkylene or phenylene linking group; and a and b areeach independently 1, 2 or 3 provided that a+b is not greater than 4.

A preferred triphenodioxazine group is of the Formula (XIII) or a saltthereof: ##STR11## wherein: each Y independently is a covalent bond,C₂₋₄ -alkylene, phenylene or sulphophenylene;

U is H or SO₃ H;

W is an optionally substituted triazine group;

T¹ and T² are halo, especially chloro, C₁₋₄ alkyl, or C₁₋₄ -alkoxy; and

each Z and R¹ independently is as hereinbefore defined.

Each Y is preferably --C₂ H₄ -- or --C₃ H₆ --, U is preferably SO₃ H,and

T¹ and T² are preferably Cl, methyl or ethyl.

W is preferably a triazine group having one or two a labile atoms orgroups.

A preferred formazan group is of the Formula (XIII) or a salt thereof:##STR12## wherein: X¹ is H, SO₃ H or Cl;

each p independently has a value of 0, 1 or 2; and

R¹ is as hereinbefore defined;

provided that the formazan group has at least one, and preferably atleast two, sulpho groups.

It is preferred that each p has a value of 1.

Where the reactive dye carries acid groups such as SO₃ H or CO₂ H thesemay be in free acid form, but are preferably in the form of a salt withone or more cations. Preferred cations are selected from an alkalimetal, ammonium and optionally substituted C₁₋₄ -alkylammonium cations.Preferred alkali metal cations include lithium, sodium and potassium. Apreferred C₁₄ -alkylammonium cation consists of a nitrogen atom havingfour substituents selected from H, C₁₋₄ -alkyl and hydroxy-C₁₋₄ -alkyl,for example mono-, di-, tri- and tetra-(C₁₋₄ -alkyl)ammonium and mono-,di, tri- and tetra-(hydroxyC₁₋₄ -alkyl) ammonium. It is preferred thatthe reactive dye is a salt with an NH₄ ⁺ cation or a mono- or poly-,methyl- or ethylammonium cation or with a mixture of two or morecations, especially a mixture of alkali metal and optionally substitutedammonium cations. Examples of optionally substituted C₁₋₄ -alkylammoniumcations include mono-, di-, tri- and tetra-methylammonium, mono-, di-,tri- and tetra-ethylammonium and mono-, di-, tri- andtetra-(2-hydroxyethyl)ammonium.

The reactive dye may be converted wholly or partially into its ammoniumor optionally substituted C₁₋₄ -alkyl ammonium salt by dissolving inwater the reactive dye in the form of a salt with an alkali metal,acidifying the solution with a mineral acid, such as hydrochloric acid,separating the precipitating compound in free acid form, suspending itin water, adjusting the pH of the suspension to 9 to 9.5 with ammonia oran optionally substituted C₁₋₄ -alkylamine to form the water-solubleammonium or C₁₋₄ -alkylammonium salt and removing the alkali metalchloride ions by dialysis. Alternatively the alkali metal ion may beexchanged for an optionally substituted ammonium ion by a conventionalion exchange method.

The dyes may be prepared by a method comprising condensation of one ormore reactive dyes having at least two reactive groups with a polyamine,preferably in a liquid medium. It is preferred that the condensation isperformed at 10° C. to 70° C., especially 20 to 50° C., more especially20 to 40° C. The liquid medium is preferably an aqueous medium,especially water. The condensation is preferably performed at a pH inthe range 6 to 9, more preferably 7.5 to 8.5. It is preferred to use anexcess of the reactive dye, for example 3 to 5 moles of the reactive dyeper mole of polyamine when the polyamine is tris(aminoalkyl)amine, morepreferably 2.5 to 3.5, especially about 3.

Examples of suitable polyamines which can be used in the method includetris(2-aminoethyl)amine, diethylene triamine, dipropylene triamine,triethylene tetramine, mono-N-(2-aminoethyl) dipropylene triamine,N,N'-bis(3-aminopropyl)butylenediamine, mono-N-(2-hydroxyethyl)triethylene tetramine, tetraethylene pentamine and pentaethylenehexamine. Preferably the polyamine has a molecular weight below 599.

The ink compositions of the present invention preferably contain from0.5% to 20%, more preferably from 0.5% to 15%, and especially from 1% to3%, by weight of the dye based on the total weight of the ink. Althoughmany ink compositions contain less than 5% by weight of colorant, it isdesirable that the dye has a solubility of around 10% or more to allowthe preparation of concentrates which may be used to prepare more diluteinks and to minimise the chance of precipitation of colorant ifevaporation of the medium occurs during storage of the ink. It ispreferred that the dye is dissolved completely in the medium to form asolution.

The ink may contain a single dye or a mixture of two or more of thehereinbefore defined dyes.

Aqueous-based ink compositions are generally used in office or homeprinters whereas organic solvent based ink compositions find use inindustrial continuous printers.

When the medium is a mixture of water and one or more water-solubleorganic solvent(s). The weight ratio of water to water-soluble organicsolvent(s) is preferably from 99:1 to 1:99, more preferably from 99:1 to50:50 and especially from 95:5 to 80:20. The water-soluble organicsolvent(s) is preferably selected from C₁₋₄ -alkanols such as methanol,ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanolor isobutanol; cyclic alkanols such as cyclohexanol and cyclopentanol;amides such as dimethylformamide or dimethylacetamide; ketones orketone-alcohols such as acetone or diacetone alcohol; ethers such astetrahydrofuran or dioxane; oligo- or poly-alkyleneglycols such asdiethylene glycol, triethylene glycol, polyethylene glycol orpolypropylene glycol; alkyleneglycols or thioglycols containing a C₂ -C₆-alkylene group such as ethylene glycol, propylene glycol, butyleneglycol, pentylene glycol or hexylene glycol and thiodiglycol; polyolssuch as glycerol or 1,2,6-hexanetriol; C₁₋₄ -alkyl-ethers of polyhydricalcohols such as 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol,2-(2-ethoxyethoxy)ethanol, 2-[2-(2-methoxyethoxy)ethoxy]ethanol,2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol; heterocyclic ketones, such as2-pyrrolidone and N-methyl-2-pyrrolidone; or mixtures containing two ormore of the aforementioned water-soluble organic solvents, for examplethiodiglycol and a second glycol or diethylene glycol and 2-pyrrolidone.

Preferred water-soluble organic solvents are 2-pyrrolidone;N-methyl-pyrrolidone; alkylene- and oligo-alkylene-glycols, such asethyleneglycol, diethyleneglycol, triethyleneglycol; and lower alkylethers of polyhydric alcohols such as or2-methoxy-2-ethoxy-2-ethoxyethanol; and polyethyleneglycols with amolecular weight of up to 500. A preferred specific solvent mixture is abinary or ternary mixture of water and diethylene glycol and/or,2-pyrrolidone or N-methylpyrrolidone in weight ratios 75-95:25-5 and60-80:0-20:0-20 respectively.

When the medium is a mixture of water and one or more water-solubleorganic solvent(s), it preferably also contains a humectant to inhibitevaporation of water and preservative to inhibit the growth of fungi,bacteria and/or algae in the solution. Examples of suitable humectantsare, propan-1,2-diol, butan-1,2-diol, butan-2,3-diol and butan-1,3-diol.

Examples of further suitable ink media are given in U.S. Pat. No.4,963,189, U.S. Pat. No. 4,703,113, U.S. Pat. No. 4,626,284 and EP4,251,50A which are incorporated herein by reference thereto.

Where the liquid medium is an organic solvent the solvent is preferablyselected from ketones, alkanols, aliphatic hydrocarbons, esters, ethers,amides or mixtures thereof. Where an aliphatic hydrocarbon is used asthe solvent a polar solvent such as an alcohol, ester, ether or amide ispreferably added. Preferred solvents include ketones, especially methylethyl ketone and alkanols especially ethanol and n-propanol.

Organic solvent based ink compositions are used where fast drying timesare required and particularly when printing onto hydrophobic substratessuch as plastics, metal or glass.

Where the medium for an ink composition is a low melting point solid themelting point of the solid is preferably in the range from 60° C. to125° C. Suitable low melting point solids include long chain fatty acidsand alcohols, preferably those with C₁₈₋₂₄ chains, or sulphonamides. Thedye may be dissolved in the low melting point solid or may be finelydispersed in it.

It is preferred that the medium is a mixture of water and one or morewater-soluble organic solvent(s).

The inks may optionally contain other components conventionally used ininks for ink jet printing. For example, viscosity and surface tensionmodifiers, corrosion inhibitors, kogation reducing additives, andsurfactants which may be ionic or non ionic.

A particularly preferred ink composition comprises:

(a) 0.5 to 20 parts of the dye;

(b) 2 to 60 parts of water-soluble organic solvent(s); and

(c) 1 to 95 parts water.

wherein all parts are parts by weight based upon the total weight of theink and the parts (a)+(b)+(c)=100.

In addition to the parts (a), (b) and (c) the ink may contain otheradditional components conventionally used in ink formulations ashereinbefore defined.

It is preferred that the ink has a pH greater than 7, more preferably apH in the range of from 7.1 to 13 and especially from 10 to 12. The pHof the ink may be adjusted to the desired level by the addition of asuitable base, for example ammonia or an optionally substituted C₁₋₄-alkylamine to the ink during its formulation.

According to a second aspect of the present invention there is provideda process for printing a substrate with an ink composition using an inkjet printer, characterised in that the ink composition is ashereinbefore in the first as part of the present invention.

A suitable process for the application of an ink composition ashereinbefore described comprises forming the ink into small droplets byejection from a reservoir through a small orifice so that the dropletsof ink are directed at a substrate. This process is commonly referred toas ink jet printing, and preferred ink jet printing processes for thepresent inks are piezoelectric ink jet printing and thermal ink jetprinting. In thermal ink jet printing, programmed pulses of heat areapplied to the ink in the reservoir by means of a resistor adjacent tothe orifice, during relative movement between the substrate and thereservoir.

It is preferred that the ink used in the process has a pH greater than7, more preferably a pH in the range of from 7.1 to 13 and especiallyfrom 10 to 12.

The substrate used in the ink jet printing process is preferably paper,plastics, a textile materials, metal or glass and is more preferablypaper, plastic or a textile material.

Preferred textile materials are natural, semi-synthetic or syntheticmaterial. Examples of natural textile materials include wool, silk, hairand cellulosic materials, particularly cotton, jute, hemp, flax aridlinen. Examples of synthetic and semi-synthetic materials includepolyamides, polyesters, polyacrylonitriles and polyurethanes.

Preferred papers are plain and treated papers which may have an acid,alkaline or neutral character.

Especially preferred substrates include overhead projector slides, plainand treated papers and synthetic or semisynthetic textile materials suchas polyester.

The preferred ink compositions used in the process is as hereinbeforedescribed.

According to a third aspect of the present invention there is provided apaper or an overhead projector slide or textile material printed with anink composition according to the first aspect of the present invention,or by means of the process according to the second aspect of the presentinvention.

According to a fourth aspect of the present invention there is provideda process for the coloration of a textile material with any of the inkcompositions according to the first aspect of the present inventionwhich comprises the steps:

i) applying the ink composition to the textile material by ink jetprinting; and

ii) heating the textile material at a temperature from 50° C. to 250° C.to fix the dye on the material.

The process for coloration of a textile material by ink jet printingpreferably comprises a pre-treatment of the textile material with anaqueous pretreatment composition comprising a water-soluble base, ahydrotropic agent and a thickening agent followed by removing water fromthe pre-treated textile material to give a dry pre-treated textilematerial which is subjected to ink jet printing in step i) above.

The pretreatment composition preferably comprises an solution of thebase and the hydrotropic agent in water containing the thickening agent.

The base is preferably an inorganic alkaline base, especially a salt ofan alkali metal with a weak acid such as an alkali metal carbonate,bicarbonate or silicate or an alkali metal hydroxide. The amount of basemay be varied within wide limits provided sufficient base is retained onthe textile material after pretreatment to promote the formation of acovalent bond between the dye and the pretreated textile material. Wherethe base is sodium bicarbonate it is convenient to use a concentrationof from 1% to 5% by weight based on the total weight of the composition.

The hydrotropic agent is present to provide sufficient water to promotethe fixation reaction between the dye and the textile material duringthe heat treatment, in step (ii) above, and any suitable hydrotropicagent may be employed. Preferred hydrotropic agents are urea, thioureaand dicyandiamide. The amount of hydrotropic agent depends to someextent on the type of heat treatment. If steam is used for the heattreatment generally less hydrotropic agent is required than if the heattreatment is dry, because the steam provides a humid environment. Theamount of hydrotropic agent required is generally from 2.5% to 50% byweight of the total composition with from 2.5% to 10% being moresuitable for a steam heat treatment and from 20% to 40% being moresuitable for a dry heat treatment.

The thickening agent may be any thickening agent suitable for use in thepreparation of print pastes for the conventional printing of cellulosereactive dyes. Suitable thickening agents include alginates, especiallysodium alginate, xantham gums, monogalactam thickeners and cellulosicthickeners. The amount of the thickening agent can vary within widelimits depending on the relationship between concentration andviscosity. However, sufficient agent is preferred to give a viscosityfrom 10 to 1000 mPa.s, preferably from 10 to 100 mPa.s, (measured on aBrookfield RVF Viscometer). For an alginate thickener this range can beprovided by using from 10% to 20% by weight based on the total weight ofthe pretreatment composition.

The remainder of the pretreatment composition is preferably water, butother ingredients may be added to aid fixation of the dye to the textilematerial or to enhance the clarity of print by inhibiting the diffusion(migration) of dye from coloured areas to non-coloured areas beforefixation.

Examples of fixation enhancing agents are cationic polymers, such as a50% aqueous solution of a dicyanamide/phenol formaldehydelammoniumchloride condensate e.g. MATEXIL™ FC-PN (available from ICI), which havea strong affinity for the textile material and the dye, even dye whichhas been rendered unreactive by hydrolysis of the reactive group, andthus increase the fixation of the dye on the textile material.

Examples of anti-migration agents are low molecular weight acrylicresins, e.g. polyacrylates, such as poly(acrylic acid) and poly(vinylacrylate).

Where the dye contains a halotriazine reactive group, it has been foundthat the yield of dye fixed to the textile material can be improved bythe addition to the pretreatment composition of certain tertiary amineswhich are capable of interacting with the reactive group so as toreplace the halogen atom and form a quaternary nitrogen leaving group,corresponding to the tertiary amine, which is displaced during fixationreaction of the dye with the textile material. It is therefore apreferred feature of the present process that the pretreatmentcomposition also contains such a tertiary amine. Any tertiary amine maybe used, but a preferred tertiary amines are substantially odourlesscompounds such as 1,4-diazabicyclo[2.2.2octane (DABCO) and susbtitutedpyridines, preferably carboxypyridines, and especially those in whichthe pyridine ring is substituted by a carboxylic acid group in the 3 or4 position, such as nicotinic or isonicotinic acid.

However, when further agents are added to the pretreatment composition,care must be taken to balance their effects and to avoid interactionswith the other ingredients of the composition.

In the pre-treatment stage of the present process the pretreatmentcomposition is preferably evenly applied to the textile material. Wherea deeply penetrated print or a deep shade is required the pretreatmentcomposition is preferably applied by a padding or similar process sothat it is evenly distributed throughout the material. However, whereonly a superficial print is required the pretreatment composition can beapplied to the surface of the textile material by a printing procedure,such as screen or roller printing, ink jet printing or bar application.

In the pre-treatment stage of the present process, water may be removedfrom the pre-treated textile material by any suitable drying proceduresuch as by exposure to hot air or direct heating, e.g. by infra-redradiation, or micro-wave radiation, preferably so that the temperatureof the material does not exceed 100° C.

The application of the ink composition to the textile material, stage(i) of the present process, may be effected by any ink jet printingtechnique, whether drop on demand (DOD) or continuous flow. The inkcomposition, preferably also contains a humectant to inhibit evaporationof water and a preservative to inhibit the growth of fungi, bacteriaand/or algae in the solution. Where the reactive group is labile even inneutral environment, hydrolysis of the reactive group on the dye in theaqueous composition and during the fixation can be inhibited by use, ashumectant, of a glycol or mixture of glycols, in which not more than onehydroxy group is a primary hydroxy group. Examples of suitablehumectants are, propan-1,2-diol, butan-1,2-diol, butan-2,3diol andbutan-1,3-diol. However, the presence of small amounts, up to about 10%,preferably not more than 5%, in total, of polyols having two or moreprimary hydroxy and/or primary alcohols is acceptable, although thecomposition is preferably free from such compounds. Where the ink jetprinting technique involves the charging and electrically-controlleddeflection of drops the composition preferably also contains aconducting material such as an ionised salt to enhance and stabilise thecharge applied to the drops. Suitable salts for this purpose are alkalimetal salts of mineral acids.

After application of the ink composition, it is generally desirable toremove water from the printed textile material at relatively lowtemperatures (<100° C.) prior to the heat applied to fix the dye on thetextile material as this has been found to minimise the diffusion of thedye from printed to non-printed regions. As with the pretreated textilematerial removal of water is preferably by heat, such as by exposure tohot air or to infra-red or micro-wave radiation.

In stage (ii) of the present process, the printed textile material issubmitted to a short heat treatment, preferably after removal of waterby low-temperature drying, at a temperature from 100° C. to 200° C. byexposure to dry or steam heat for a period of up to 20 minutes in orderto effect reaction between the dye and the fibre and thereby to fix thedye on the textile material. If a steam (wet) heat treatment is used,the printed material is preferably maintained at 100-105° C. for from 5to 15 minutes whereas if a dry heat treatment is employed the printedmaterial is preferably maintained at 140-160° C. for from 2 to 8minutes.

After allowing the textile material to cool, unfixed dye and otheringredients of the pretreatment and dye compositions may be removed fromthe textile material by a washing sequence, involving a series of hotand cold washes in water and aqueous detergent solutions before thetextile material is dried.

According to a fifth aspect of the present invention there are providedtextile materials, especially cellulosic textile materials, colouredwith the ink composition according to the first aspect of the presentinvention or by means of the a process according to the fourth aspect ofthe present invention.

According to a sixth aspect of the present invention there is provided atoner resin composition comprising a toner resin and a dye characterisedin that the dye is as hereinbefore defined in the first aspect of thepresent invention.

The toner resin is preferably a thermoplastic resin for example, astyrene or substituted styrene polymer or copolymer, for example, apolystyrene or styrene-butadiene copolymer, especially a styrene-acryliccopolymer, for example, a styrene-butyl methacrylate copolymer. Othersuitable toner resins include polyesters, polyvinylacetate, polyalkenes,polyvinylchloride, polyurethanes, polyamides, silicones, epoxyresins andphenolic resins. Examples of toner resins are given inElectrophotography by R. M. Scharfert (Focal Press), U.S. Pat. No.5,143,809, GB 2,090,008, U.S. Pat. No. 4,206,064 and U.S. Pat. No.4,407,928 which are incorporated herein by reference thereto.

The toner resin composition preferably contains from 0.1% to 20% of thedye of Formula (1) or a mixture of dyes of Formulae (1) and (4) ormixture of dyes of Formulae (1) and (5) more preferably from 3% to 10%based on the total weight of the toner resin compositions.

The toner resin composition may be prepared by any method known to theart which typically involves mixing the toner resin with the dye ofFormula (1) or mixtures of is dyes of Formulae (1) and (4) or mixture ofdyes of Formulae (1) and (5) and optionally a charge control agent (CCA)by kneading in a ball mill above the melting point of the resin.

Generally, this involves mixing the molten toner resin composition forseveral hours at temperatures from 120 to 200° C., in order to uniformlydistribute the opional CCA and dye throughout the toner resin. The tonerresin is then cooled, crushed and micronised until the mean diameter ofthe particles is preferably below 20 μm and, for high resolutionelectro-reprography, more preferably from 1 to 10 μm. The powdered tonerresin composition so obtained may be used directly or may be dilutedwith an inert solid diluent such as fine silica by mixing for example ina suitable blending machine.

The CCA is present in the toner at from 0.1 to 5% based upon the totalweight of the toner.

Further suitable examples of CCA's are described in WO 94123344 which isincorporated herein by reference thereto.

The invention is further illustrated by the following Examples in whichall parts and percentages are by weight unless otherwise stated.

EXAMPLE 1

Preparation of ##STR13## Stage a)

1-hydroxy-2-(1,5-disulphonaphth-2-ylazo)-6-N-(4,6-dichloro-s-triazin-2-yl)methylamino]-naphthalene-3-sulphonicacid was prepared by coupling diazotised2-aminonaphthalene-1,5-disulphonic acid ontoN-acetyl-2-methylamino-5-hydroxynaphthalene-7-sulphonic acid, removingthe acetyl group by heating to 80° C. in 2N sodium hydroxide solutionand reacting the resultant dyebase with cyanuric chloride at 0-5° C.

Stage b)

Tris(β-aminoethyl)amine (1.246 g) was added to a stirred solution of theproduct from stage a) (36 g, MI 1221) in water (250 cm³). The mixturewas stirred at 50° C., pH 8.5, for 2 hours, cooled and methylatedspirits was added slowly with stirring, The precipitated dye wascollected and dried to give the title product (23 g, MI 2914) having aλmax at 484 nm.

EXAMPLE 2

Preparation of ##STR14## Stage a)

2-(1-sulphonaphthyl-2-azo)-8-(4,6-dichloro-s-triazin-2-ylamino)-1-hydroxynaphthalene-3,6-disulphonic acid was prepared by condensing cyanuricchloride with1-hydroxy-2-(1-sulphonaphthyl-2-azo)-8-aminonaphthalene-3,6-disulphonicacid at 0-5° C. and pH6.

Stage b)

Tris(β-aminoethyl)amine (0.684 g, 96% strength) was added to a stirredsolution of the product from stage a) (0.0148 m) in water (250 cm³). Themixture was stirred at 50° C. and pH 8.5 for 5 hours. A further portionof the product from stage a) (0.0029 mol) was added and the mixture wasstirred for a further 2 hours at 50° C. The mixture was allowed to coolto room temperature, salt solution (8% w/v) was added with stirring andthe resultant precipitate collected and dried to give the title product(11.0 g, 76% strength) having a λmax at 518 nm and εmax of 102,166.

EXAMPLE 3

Preparation of ##STR15## Stage a)

1-hydroxy-2-(2-sulpho4methyl phenylazo)-8-(4,6-dichloro-a-triazin-2-ylamino)naphthalene-3,6-disulphonicacid was prepared by coupling diazotised 2-amino-5-methylbenzenesulphonic acid onto 1-hydroxy-8-(dichloro-a-triazinylamino)naphthalene-3,6-disulphonic acid.

Stage b)

Tris(β-aminoethyl)amine (1.01 g) was added to a solution of the productfrom stage a) (43 g, MI 1599) in water (300 cm³). The mixture wasstirred at 50° C. and pH 8.5 for 2 hours then allowed to cool to roomtemperature. Methylated spirits was added slowly with stirring and theresultant precipitate collected and dried to give the title product (30g) having a λmax at 516 nm.

EXAMPLE 4

The method of Example 2 was repeated except that in place istris-(β-aminoethyl)amine there was used an equimolar amount ofdiethylene triamine. The resultant product had a λmax at 518 nm.

EXAMPLE 5

The method of Example 3 was repeated except that in place istris-(β-aminoethyl)amine there was used an equimolar amount ofdiethylene triamine. The resultant product had a λmax at 516 nm.

EXAMPLE 6 ##STR16##

A solution of1-hydroxy-6-[N-methyl-N-(dichloro-s-triazinyl)]-amino-2-[3-methyl4-(2,5-disulphophenylazo)phenyl azo] naphthalene-3-sulphonic acid (0.0248 mmol) andtris(β-aminoethyl)amine (0.0083 mmol) was stirred at pH 8.5 and 45-50°for 6 hours. On cooling, potassium chloride solution (7.5% w/v) wasadded and the precipitate was collected and dried to give the titleproduct having a λmax at 522 nm, εmax 128,000.

EXAMPLE 7

Preparation of a reactive dye of the formula (10): ##STR17## wherein Dis 1-hydroxy-2-(2-sulphophenylazo)-3,6-disulpho naphthyl-8-amino.

Diethylene triamine (8.7 mmol) was added to a solution of1-dichloro-s-triazinylamino-1-hydroxy-2(2¹-sulphophenylazo-)naphthalene-3,6-disulphonic acid (27.3 mmol) in water(200 cm³). The mixture was stirred at 50° C. and pH 8.5 for 8 hours. Oncooling the solution was added to methylated spirits (740p, 1 liter) andthe precipitated solid was collected and dried to give the title product(7.8 mmol) having a λmax at 506 nm.

EXAMPLE 8

Preparation of a dye of formula (10) wherein D is ##STR18## Stage a)

1-(4-sulphophenyl)-3-carboxy-4-(2-sulpho-4-dichloro-s-triazinylamino-phenylazo)pyrazol-5-one was prepared by condensation of1-(4-sulphophenyl)-3-carboxy-4-(4-amino-2-sulphophenyl azo)pyrazol-5-one with cyanuric chloride at pH 6.5.

Stage b)

Diethylene triamine (8.3 mmol) was added to a solution of the productfrom stage a) (26.3 mmol) in water (200 cm³). After stirring for 4 hoursat 50° C. and pH 8.5 the mixture was added, with stirring, to methylatedspirits. The precipitate was filtered-off and dried to give the titleproduct (4.5 mmol) having a λmax at 449 nm.

EXAMPLE 9

Preparation of a dye of formula (10) wherein D is of the formula:##STR19##

Stage a)

N-(dichloro-s-triazinyl)-3-ureido-4-(3,6,8-trisulpho naphthyl-2-azo)aniline was prepared by condensation, at 0° C. to 5° C. and pH 6.5, ofcyanuric chloride with 3-ureido-4-(3,6,8-trisulphonaphthyl-2-azo)aniline.

Stage b)

Diethylenetriamine (5.4 mmol) was added to a solution of the productfrom stage a) (16.2 mmol) in water (200 cm³). The mixture was stirred at50° C. and pH 8.5 for 15 hours. After cooling to room temperature themixture was added to methylated spirits (740 p, 1 liter) and theprecipitated solid collected and dried to give the title product (4mmol) having a λmax at 431 nm.

EXAMPLE 10

Stage a)

The method of Example 3, stage b), was followed except that in place ofthe product from step a) there was used 1-hydroxy-2-(2¹ -sulpho-5¹-acetylaminophenylazo)-8-(4,6-dichloro-5-triazin-2-ylamino)naphthalene-3,6-disulphonic acid. The resultant reactive dye had a λmaxat 505 nm.

EXAMPLE 11

Ink jet printing inks containing dyes described in the foregoingexamples may be prepared according to the following formulations shownin Table I wherein the figures denote parts by weight for each statedcomponent:

The following abbreviations are used:

PG =propylene glycol,

DEG=diethylene glycol,

NMP=N-methyl pyrollidone,

DMK=dimethylketone,

IPA=isopropanol,

MEOH=methanol,

2P=2-pyrollidone,

MIBK=methylisobutyl ketone,

CET=Cetyl ammonium bromide (a surfactant),

BAS=1:1 mixture by weight of ammonia and methylamine,

PHO=Na₂ HPO₄.

                                      TABLE 1                                     __________________________________________________________________________    Dye From                                                                            Dye                                                                       Example No. Content Water PG DEG NMP DMK PHO CET IPA MEOH 2P MIBK           __________________________________________________________________________                                                 BAS                               1    2.0 80  5    6  4               5      3                                   2 3.0 90  5 2  0.2                                                            3 1.0 85 5  2 2  0.1  5 1                                                     4 2.1 91  8        1                                                          5 3.1 86 5     0.2 4   5                                                      6 1.1 81   9  0.5 0.5   9                                                     7 2.5 60 4 15  3 3   6 10  5 4                                                8 1.9 70  20      10                                                          9 2.4 75 5 4      6  5 5                                                     10 4.1 80 3 5 2 10   0.3                                                      11 3.2 65  5 4 6   5 4 6 5                                                     2 4.6 96        4                                                             3 0.8 90 5      5                                                             4 1.2 80 2 6 1 5   1  4  1                                                    5 1.8 80  5       15                                                          6 2.6 84   11       5                                                         7 3.3 80 2   10     2  6                                                      8 1.7 90    7 0.3  3                                                          9 1.5 69 2 20  2 1     3 3                                                   10 1.6 91   4      4  1                                                        1 10.0  70 5  6 4     5                                                       2 8.0 85  5 2                                                                 3 12.0  77 5  2    2  2                                                       4 9.0 76  10  2      3                                                        5 11.5    77.3 5     0.2   1 5                                                6 7.0 80   9 1     3                                                          8 10.4    64.6  15      10                                                   15 8.5 73 2 6 1 5     4    0.5                                                16 12.5  75    8 0.5  4                                                       17 10.0  70   10       12                                                      9 11.0  73 5  6      5                                                       20 10.0  40 4 15  3 3   6 10  5 4                                           __________________________________________________________________________

The inks described in Table 1 can be printed onto substrates such aspaper and cotton using an ink jet printer.

EXAMPLE 12

The ink compositions shown in Table 1 may be applied to a textilematerial such as cotton using an ink jet printer. Preferably the textileis pre-treated with a composition comprising:

2.5 pts sodium bicarbonate;

15pts of a 10% aqueous solution of sodium alginate thickening agent;

15 pts of urea;

47.5 pts of water; and

20 parts of Composition A shown in Table 2.

                  TABLE 2                                                         ______________________________________                                        Composition A                                                                     Component             Parts by Weight                                     ______________________________________                                        Urea                  25                                                        Distearyl Dimethyl Ammonium Chloride 2.3                                      Isopropyl Alcohol 0.8                                                         Castor Oil + 2.5 Ethylene Oxide 2.2                                           Castor Oil + 4.0 Ethylene Oxide 0.36                                          Sodium Lauryl Sulphate 0.010                                                  Methanol 0.007                                                                Formaldehyde 0.0001                                                           Tallow Amine + 15 Ethylene Oxide 0.25                                         Acetic Acid (80%) 0.05                                                        Water 69.0                                                                  ______________________________________                                    

The textile material should be thoroughly soaked with the pretreatmentcomposition in a padding bath and the excess liquor removed by mangling.The material should then be dried in hot air at 100° C. prior toapplication of the inks shown in Table 1 by an ink jet printer.

The printed textile is preferably heated at a temperature from 100 to200° C. after application of the ink composition.

We claim:
 1. An ink composition comprising a water-soluble reactive dyecomprising at least three chromophoric groups linked to a polyamine; anda medium comprising at least one of a low melting point solid, anorganic solvent and a mixture of water and one or more water-solubleorganic solvent(s).
 2. An ink composition according to claim 1 whereinthe water-soluble reactive dye comprises 3, 4 or 5 chromophoric groupslinked to a polyamine.
 3. An ink composition according to claim 1wherein the polyamine is a linear or branched polyamine.
 4. An inkcomposition according to claim 1 wherein the polyamine to which thechromophoric groups are linked consists of at least three amino groupsjoined together by optionally substituted aliphatic groups.
 5. An inkcomposition according to claim 1 wherein the chromophoric groups arelinked to the polyamine by means of reactive triazine or reactivepyrimidine groups.
 6. An ink composition according to claim 1 whereinthe polyamine is of formula (I) or (II) wherein each R¹ independently isH or alkyl, n has a value of 2 to 10 and p has a value of 2 to 6:##STR20## .
 7. An ink composition according to claim 1 wherein thewater-soluble reactive dye contains at least 3 groups of the formula(III): ##STR21## wherein: m is from 1 to 6;Q is H, optionallysubstituted alkyl or alkylene; Y is a labile atom or group; and D is achromophoric group.
 8. An ink composition according to claim 1 whereinthe water-soluble reactive dye is of the formula N(Z)₃ wherein each Zindependently is of the formula (III): ##STR22## wherein: m is from 1 to6;Q is H or optionally substituted alkyl; Y is a labile atom or group;and D is a chromophoric group.
 9. An ink composition according to claim1 wherein the water-soluble reactive dye is of the formula (IV):##STR23## wherein t is 2, 3 or 4;r is 3, 4or 5; R¹ is H or alkyl; qis(t+3)-r; Y is a labile atom or group; m is from 1 to 6; D is achromophore; andat least one D is a chromophore other than an azochromophore.
 10. An ink composition according to claim 1 wherein themedium comprises water and one or more water-soluble organic solvent(s).11. An ink composition according to claim 1 comprising:(a) 0.5 to 20parts of the dye; (b) 2 to 60 parts of water-soluble organic solvent(s);and (c) 1 to 95 parts water; wherein all parts are by weight and theparts (a)+(b)+(c)=100.
 12. An ink composition according to claim 1wherein the ink has a pH greater than
 7. 13. A process for printing asubstrate with an ink composition comprising forming the ink into smalldroplets by ejection from a reservoir through a small orifice so thatthe droplets of the ink are directed at a substrate wherein the inkcomposition is as defined in claim
 1. 14. A paper, an overhead projectorslide or a textile material printed with an ink composition according toclaim 1 or by means of the process according to claim
 13. 15. A processfor the coloration of a textile material with any of the inkcompositions defined in claim 1 which comprises the steps:(i) applyingthe ink composition to the textile material by ink jet printing; and(ii) heating the textile material at a temperature from 50° C. to 250°C. to fix the dye on the material.
 16. A toner resin compositioncomprising a toner resin and a dye wherein in the the dye is as definedin claim 1.